Safety and tolerability
Just like with any drug, it is important for cannabis users to inform themselves on the safety and tolerability of cannabis products. Even though cannabis is safer than numerous medicines, like opioids described below, it can be harmful to users with certain pre-existing conditions.
A frequently asked question is: “Why can you directly die of opioids but not of cannabis?” Opioids are compounds that are used to treat pain symptoms. They are highly addictive, and, for a large part due to mismanagement, many people use opidoids for their addiction instead of their pain, referred to as the ‘opioid crisis’.1
Originally extracted from seeds of the poppy plant (Papaveraceae
family), morphine has a much lower potency than most synthetic opioids that are available nowadays. Fentanyl, for example, can be 10 to 400 times more potent.2
Besides pain relief, opioids have many other effects that lead to, for example, constipation or a reduced respiratory rate.
How Cannabis Is Different
Unlike the case with opioids, which can cause lethal respiratory depression when overdosed, there have not been any reports on human lethal overdosing with cannabis.3, 4
This is due to the fact that, unlike alcohol and opioids, cannabis only minimally interacts with the part of the brain involved in vital signs, such as heart rate and respiration. With alcohol and opioid overdose, the brain stops sending a signal to breathe, which does not happen with cannabis.5
Why Cannabis Is Not Safe For Everyone
Just because it is very hard to overdose on cannabis, that does not mean cannabis is a “safe” drug. In patients with high risk factors of heart attacks, cannabis can trigger a heart attack.6, 7
Likewise, it has been shown that cannabis can lead to psychosis and schizophrenia in patients with pre-existing psychotic disorders.8, 9
It has been shown that long-term cannabis use has been associated with a decline in cognitive function, however, after a few days of abstinence, there seems to be a reversal of this decline.10, 11
Read the page Health and disease
to learn about the effects of cannabis on different medical conditions.
- Lovrecic, Barbara; Lovrecic, Mercedes; Gabrovec, Branko; Carli, Marco; Pacini, Matteo; Maremmani, Angelo G. I.; Maremmani, Icro (2019). Non-Medical Use of Novel Synthetic Opioids: A New Challenge to Public Health. Int. J. Environ. Res. Public Health, 16(2), 177.
- Terenius, L. (1974). Contribution of ‘receptor’ affinity to analgesic potency. Journal of Pharmacy and Pharmacology, 26(2), 146-148.
- Calabria, Bianca; Degenhardt, Louisa; Hall, Wayne; Lynskey, Michael (2010). Does cannabis use increase the risk of death? Systematic review of epidemiological evidence on adverse effects of cannabis use. Drug and Alcohol Review, 29(3), 318--330.
- Walker, J. Michael; Huang, Susan M. (2002). Cannabinoid analgesia. Pharmacology & therapeutics, 95(2), 127--35.
- White, J. M.; Irvine, R. J. (1999). Mechanisms of fatal opioid overdose. Addiction (Abingdon, England), 94(7), 961--972.
- Beaconsfield, Peter; Ginsburg, Jean; Rainsbury, Rebecca (1972). Marihuana Smoking. New England Journal of Medicine, 287(5), 209--212.
- Mittleman, Murray A.; Lewis, Rebecca A.; Maclure, Malcolm; Sherwood, Jane B.; Muller, James E. (2001). Triggering Myocardial Infarction by Marijuana. Circulation, 103(23), 2805--2809.
- Marconi, Arianna; Di Forti, Marta; Lewis, Cathryn M.; Murray, Robin M.; Vassos, Evangelos (2016). Meta-analysis of the Association Between the Level of Cannabis Use and Risk of Psychosis. Schizophrenia Bulletin, 42(5), 1262--1269.
- Prescott, C. A.; Gottesman, I. I. (1993). Genetically mediated vulnerability to schizophrenia. The Psychiatric clinics of North America, 16(2), 245--267.
- Pope, Harrison G.; Gruber, Amanda J.; Hudson, James I.; Huestis, Marilyn A.; Yurgelun-Todd, Deborah (2002). Cognitive measures in long-term cannabis users. Journal of clinical pharmacology, 42(S1), 41S--47S.
- Solowij, N. (1995). Do cognitive impairments recover following cessation of cannabis use?. Life sciences, 56(23-24), 2119--26.